Hello,
I need to add a unique constraint on table U_SMCSHIPPING column SERVICER_LN_NUM . I know there are presently rows that violates this constraint (meaning, there are duplicate rows).
I used the following statement and got an error message.

ALTER TABLE EMPOWER.U_SMCSHIPPING ADD CONSTRAINT CHASE_NUM_UNIQUE UNIQUE(SERVICER_LN_NUM) ENABLE NOVALIDATE
*
ORA-02299: cannot validate (EMPOWER.CHASE_NUM_UNIQUE) - duplicate keys found

Why I am getting this error msg when I'm explicitely telling it not to validate. All I want is to prevent future duplications.
Please help. it's very urgent.
Oracle 8i version 8.1.6 Enterprise Edition.

Thanks in advance for your help
Robel Girma